Shunt for electric light starter



March 8, 1966 M. SALlT 3,23%,714

SHUNT FOR ELECTRIC LIGHT STARTER Filed March 20, 1962 62 FIG 4 INVENTOR.

ATTO/Q/VEYS United States Patent 3,239,714 SHUNT FOR ELECTRIC LIGHT STARTER Morris Salit, 2t) Vesey St., New York 7, N.Y. Filed Mar. 20, 1962, Ser. No. 180,958 1 Claim. (Cl. 31598) This invention relates to an adapter for use with a fluorescent lamp fixture and more particularly to a device for use as a shunt in a fluorescent lamp fixture.

Conventional fluorescent lamp fixtures in the past have had incorporated therein a starter assembly adapted to supply current for heating filaments and a sufficiently high voltage surge to cause a fluorescent lamp to ignite when the operating switch is closed. This starter conventionally is in the shape of a small metal can which contains a bimetallic strip and is connected within the ballast circuit of the fluorescent lamp. The metal can is cylindrical in shape and fits within a circular recess in the lamp fixture. It has two depending terminals or prongs which fit within sockets therefor to complete the operative electrical lamp circuit. The starter is made so that it can be replaced when burned out.

Recently, during further development of fluorescent lamps, there has been devised a rapid start type of lamp which works on relatively high voltage and does not require the use of a starter. This rapid start type lamp will not work efliciently in an old type fluorescent lamp fixture which has a starter unit incorporated therein. Accordingly, the old type of fixture must either be discarded or be completely rewired to serve for use with a rapid start fluorescent lamp and the sockets for each starter must be eliminated, which often requires costly repairs and reconstruction.

It is therefore an object of the present invention to provide an adapter for use in converting a fluorescent lamp fixture constructed to employ a starter whereby only minor changes in the wiring circuit need be made and wherein the adapter contains a shunt for bypassing the sockets of the fluorescent lamp fixture.

In accordance with an illustrative embodiment of the invention there is provided an adapter for completing the operative electrical circuit of the fluorescent lamp fixture so that rapid start fluorescent lamps can be used in old type fixtures. The adapter contains a shunt and is in the shape of a cylindrical body preferably formed of synthetic plastic insulating material in which the shunt is imbedded. The shunt has two prongs or terminals which fit within the sockets in which the starter unit previously fit so as to convert the old type lamp fixture into one for a rapid start fluorescent lamp.

Still further objects and features of this invention reside in the provision of an adapter for use in converting fluorescent lamp fixtures for use with rapid start fluorescent lamps that is simple in construction, inexpensive to manufacture, and etficient in use so as to permit wide use and distribution.

These, together with the various ancillary objects and features of the invention which will become apparent as the following description proceeds, are attained by this adapter, a preferred embodiment of which has been illustrated in the accompanying drawings, by way of example only, wherein:

FIG. 1 is an elevational view of an embodiment of the invention;

FIG. 2 is an end elevational view of the adapter;

FIG. 3 is a perspective detailed view of the adapter having a portion broken away to show other parts in detail;

FIG. 4 is a wiring diagram of a conventional old type fluorescent lamp circuit employing starters; and

FIG. 5 is a schematic wiring diagram illustrating how 3,239,714 Patented Mar. 8, 1966 the circuit arrangement of FIG. 4 is modified for use with rapid start lamps by employing the adapters.

With continuing reference to the accompanying drawings wherein like reference numerals designate similar parts throughout the various views, and with initial attention directed to FIG. 4, reference numeral 10 generally designates an electrically operative circuit for exciting a pair of fluorescent lamps 12 and 14. An old type fluorescent fixture, not shown, employs a ballast 16 and a pair of starters 18 and 20 which are disposed in suitable sockets for the starters 18 and 20. These sockets are provided in the fixture in a location so that the starters are readily accessible for replacement should they become burned out. The starters 18 and 20 are provided with prongs or terminals 22, 24, 26, 28 which are adapted to fit in the socket which is of a conventional construction for completing electrical connection conductors 30, 32, 34 and 36 respectively.

The terminal or contact end 38 of the fluorescent lamp 12 is connected by conductor 32 to the terminal 24 of starter 18 and the other starter terminal 22 is connected to the terminal or contact end 40 of the lamp 12 by conductor 30. Also connected to the contact end 38 of the lamp 12 is the conductor 42 which in turn is connected through conductors 44 and 46 to the ballast 16. Conductor 48 connects the contact end 40 to the ballast 16.

The contact end 60 of the fluorescent lamp 14 is connected through conductor 36 to the starter 20 and thence connected through conductor 34 to the ballast 16. Conductor 62 is connected to the contact end 60 and to conductor 44 and through conductor 44 to the ballast 16. The other contact end 66 of the lamp 14 has conductors 68 and 70 connected thereto.

As can be seen in FIG. 4, the ballast 16 is a preheat ballast which normally requires the use of a condenser. In order to adapt a fluorescent lamp fixture of the type which employed a preheat ballast such as the ballast l6 and lamps 12 and 14, as well as starter 18 and 20, to use fluorescent lamps of the rapid start type 12 and 14', a rapid start ballast 16' is employed, and in lieu of starters l8 and 20, adapters 1.18 and are employed The ballast 16 is of the conventional and well known type which is adapted to supply to rapid start lamps sufficient voltage to ignite such lamps without the need for starters. Such rapid start ballast is shown, for example, in US. Patent No. 2,861,217 of A. E. Feinberg, and includes a pair of input terminals and multiple pairs of output terminals. In FIG. 5 herein, the input terminals of ballast 16' are indicated connected by a pair of leads extending from the upper, left-hand side of ballast 16' to a power source, and three pairs of output terminals are indicated connected to the remaining leads of the circuit shown. The adapters 118 and 120 are adapted to be disposed in the sockets normally provided for the starters l8 and 26!. The only circuit changes necessary to be made is that conductor 30 is cut and the portion 30' of conductor 30 is connected to the conductor 34 which is connected to the ballast. The conductor 44 is connected to the rapid start ballast 16' in the manner shown and the end 30" of the conductor 30 which has been cut is now also connected to the rapid start ballast 16. Otherwise, the wiring remains identical.

Each of the adapters 118 and 120 are of the same construction as can be seen best in FIGS. 1, 2 and 3. The adapter 120 is cylindrical in shape and is formed preferably by molding of a synthetic plastic insulating material such as Bakelite, polystyrene, polyethelene, polyvinyl chloride, or other suitable material. Embedded in the body 120 is a U-shaped shunt 122 which terminates in terminals or prongs 124 and 126 which extend outwardly of the body and are adapted to fit in the sockets provided in the conventional fluorescent lamp fixture.

In use, the shunt 122 interconnects conductors 32 and 30 as well as conductors 36 and 24 to complete the operative electrical circuit in the circuit illustrated in FIG. 5.

The adapters 118 and 120 are made cylindrical in shape and of the same size as conventional starter units so that they may be quickly and easily inserted in the sockets of an existing fixture which formerly received the starter units. As a result, existing fixtures may be readily adapted for reception and efiicient operation of rapid start lamps.

Instead of embedding the shunt 122 in a molded plastic body 120, the shunt may be mounted within a hollow dielectric casing of the same cylindrical shape. Alternatively, the shunt may be mounted in the usual hollow metal case of the conventional starter, and the metal case covered by a dielectric cap.

A latitude of modification, change and substitution is intended in the foregoing disclosure and in some instances some features of the invention [Will be employed without a corresponding use of other features. Accordingly, it is appropriate that the appended claim be construed broadly and in a manner consistent with the spirit. and scope of the invention herein.

What I claim is:

A method of adapting a starter type fluorescent lamp fixture for use in conjunction with a rapid start fluorescent lamp wherein the starter-type fluorescent lamp fixture is of the type including at least one pair of lampholders having opposite pairs of terminals and a starter socket member including a pair of terminals; said method comprising the steps of connecting a first pair of lampholder terminals in series with said starter socket terminals to a pair of output terminals of a rapid start ballast, connecting the second of said lampholder terminal pairs to another pair of output terminals of said rapid start ballast, and inserting an adapter plug member including a conductor within said starter socket member to shunt the starter socket terminals.

References Cited by the Examiner UNITED STATES PATENTS DAVID J. GALVIN, Primary Examiner. 

